4x4 Parts Shop, Colorado Springs, CO 80915

[threecol_two]Well, as you know, one thing always leads to another. Here’s a perfect example. When the brakes failed to stop P3’s power train, the call was made to replace the torque converter. But that got Nate thinking of alternative forms of power trains. The first thing was the stock ‘345’ ended up being a 304, and that had a ‘stock’ TF727 with (as we know) a stock torque converter. All of this led Nate to believe that he needed a stronger power train.

Before you start thinking “the stock one overpowers the brakes, why do you need a larger one!?!”, remember that the brakes weren’t at fault. They work brilliantly. The problem we ran into is something professional rock crawlers have faced for the longest time, too much crawl makes it impossible to stop with it in drive. Slowing down from street speeds is fine, but since an automatic transmission puts power to the wheels even when you’re standing on the brakes, when you have it in super-compound low, its just too much power.

The fix is easy, get a torque converter that has a higher stall. The higher stall doesn’t apply power till the engine reaches higher RPM, and although it can give a little power to the wheels when stopped, its not enough to overpower the brakes. The side-blessing of this is when you’re climbing, crawling, pulling the higher stall applies power after the engine reaches its power band.

The question is what stall do you want. Since IH motors begin making power at low-RPMs, we chose an 1800 rpm stall. Remember, the stall is where the torque converter applies 100% power to the wheels, so P3 will still move under light throttle, it’ll have more time to build RPM’s before all power hits the axles.

Needless to say, the t-case, Creeper, and stock transmission had to be pulled to get the torque converter out. And that’s were the alternative drive trains came into play. The thought was “Heck, with everything about out, lets just pull the engine and stick something else in it!” So immediately Nate started thinking Viper Motor (which is a 8.0 liter V-10), but its physical dimensions are over 4′ long and it simply would not fit into the Scout’s engine bay without major modifications.

To make a very long story short, the previous drive train was removed and sold to make way for ‘something else’. When ‘something else’ meant a ton more time and expense, Nate decided to make due with what the factory provided.

Finally the decision was made to spruce up the factory 304 and add fuel injection. After all, the Scout drove fine before, why not after right? So with a visit to an old friend Craig Brooks (of Brooks Racing Engines) we had a revamped 304 with ported & decked heads. This not only flows better, it bumps the compression a touch for more power. A TurboCity TBI kit and Airaid intake system rounded off the induction side of the the engine, while a GM HEI conversion provided a stronger ignition.

With the engine in place, we turned back to the transmission dilemma. When all was said and done, it was decided that if P3 was going to get ‘stock’ stuff, it wouldn’t need the full treatment. Therefore, Colorado Transmissions custom built a high-horse 1800 Stall converter and Art Carr provided an RV gear set and bolt-in sprag (these components are the main things that seriously beef the transmission up to handle monster amounts of torque/power). A tail shaft housing from a Jeep TF727 allowed us to bolt on a 6-bolt (round pattern) Atlas II (3.8 drop).

This combination was a pretty good fit in the Scout, but we ran into one small snag. Since the drive lines, pinion angles and front caster was already set to a power train with the extended length of a creeper box, we needed to find something about 5″ longer. The answer, a Klune-V.

This that, and a couple of High Angle Driveline’s CV-Shafts, we were again ready for the road.

In case you’re keeping track. The crawl ratio has gone threw the roof. All things considered, P3 is at 259.2:1 (That’s calculating a 2.77 first, 2:1 for the torque converter, 2.7:1 for the Klune,. 3.8:1 for the Atlas and 4.56:1 in the axles) Anyone need a house pulled off its foundation? And finally the drive train if finished!

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